Carbonyl Iron/Graphite Double-Layer Structural Absorbing Composite

2012 ◽  
Vol 557-559 ◽  
pp. 390-393
Author(s):  
Jing Lan Deng ◽  
Bing Feng
Keyword(s):  
Composite Materials ◽  
Carbonyl Iron ◽  
Impedance Matching ◽  
Resin Matrix ◽  
Frequency Range ◽  
Matching Layer ◽  
Peak Absorption ◽  
Absorbing Material ◽  
Absorbing Layer ◽  
Stealth Materials

A study of a new structured composite absorbing material, prepared using carbonyl iron and graphite as absorbers within a resin matrix. The study investigated the effects of varying the concentration of absorbing agent within the layers of the absorbing composite. Results show that the best absorbency was achieved when the impedance-matching layer contained 20% carbonyl iron content and the absorbing layer contained 35% graphite. The peak absorption was -20.19 dB, with a bandwidth of 7.3GHz (R< -10 dB) in the frequency range of 8 to 18 GHz. This work will certainly have significance guiding research on the application of stealth materials and composite materials.

Absorbing Properties of Composite Material Plates of Multi-Layer Absorbing Structure

2011 ◽  
Vol 287-290 ◽  
pp. 9-14 ◽  
Author(s):  
Jing Lan Deng ◽  
Bing Feng
Keyword(s):  
Composite Material ◽  
Impedance Matching ◽  
Graphite Powder ◽  
Effective Bandwidth ◽  
Frequency Range ◽  
Absorption Frequency ◽  
Peak Absorption ◽  
The World ◽  
Absorbing Material ◽  
High Absorption

Microwave absorbing material is currently being more and more widely applied in the world. However, conventional absorbent coating material cannot fulfill the complex current requirements of science and technology to have a wide absorption frequency band, and high absorption. This paper describes composite material plates with a multi-layer absorbing structure designed according to impedance-matching and attenuation principles, producing two- and three-layer absorbing structures. Twelve samples were made, containing graphite powder and manganese dioxide at varying concentrations. The results show that in the frequency range 8-18 GHz, the peak absorption of double-layer samples is -12.3dB, the effective bandwidth (R < -10 dB) is 1.8GHz. The absorption peak of three-layer samples is -18 dB, and the effective bandwidth (R < -10 dB) is 8GHz. The findings of this research are useful in improving the absorption bandwidth of absorbing material.

scholarly journals Microwave absorption and mechanical properties of double-layer cement-based composites containing different replacement levels of fly ash

2018 ◽  
Vol 25 (4) ◽  
pp. 707-714 ◽  
Author(s):  
Yuefang Zhang ◽  
Shunhua Liu ◽  
wanJun Hao
Keyword(s):  
Mechanical Properties ◽  
Fly Ash ◽  
Double Layer ◽  
Impedance Matching ◽  
X Ray Diffraction ◽  
Replacement Ratio ◽  
Matching Layer ◽  
Optimal Replacement ◽  
Zn Ferrite ◽  
Absorbing Layer

Abstract Double-layer absorbing cement-based composites with the thickness of 10 mm were prepared, including different replacement levels of fly ash (FA) in the absorbing layer as well as the matching layer for impedance matching. Waste polyethylene terephthalate bottle fragment was introduced as electromagnetic transparent reinforcement aggregate. Carbon black was used to be original absorbent in the absorbing layer. The microstructure and electromagnetic parameters of FA were closely looked at through scanning electron microscope, X-ray diffraction, and analyzer of vector network. The absorption and mechanical properties of cement-based composites were tested. It turned out that when the optimal replacement ratio of FA in the absorbing layer and matching layer gets to 50%:30%, the minimum value of reflection loss achieves −22.3 dB at 13.2 GHz; also, the value of absorption bandwidth that is effective (<−8 dB) is 6.4 GHz. Ni-Zn ferrite proves to be a feasible absorbent that is additional for the matching layer compared to what is added to the absorbing layer. The compressive strength of all the mixtures decreased, while the flexural strength decreased first and then increased with the rise of the FA replacement level.

Microwave Properties of Composite Ba0.5Sr0.5Fe11.7Mn0.15Ti0.15O19/La0.7Ba0.3MnO3 Material

2014 ◽  
Vol 896 ◽  
pp. 440-443 ◽  
Author(s):  
Viktor Vekky Ronald Repi ◽  
Azwar Manaf ◽  
Bambang Soegiono
Keyword(s):  
Composite Materials ◽  
Ball Mill ◽  
Composite System ◽  
Lanthanum Manganite ◽  
Strontium Hexaferrite ◽  
Frequency Range ◽  
Crystalline Materials ◽  
Barium Strontium ◽  
Wide Range ◽  
Absorbing Material

Mn-Ti substituted Barium - Strontium Hexaferrite and Barium – Lanthanum Manganite both well established materials which have been shown poses microwave absorbtion properties. As the properties of composite system are a composition sensitive, composite materials must be properly designed to meet a specific application. In this paper, we report our recent investigation on microwave absorbtion properties of composite Ba0.5Sr0.5Fe11.7Mn0.15Ti0.15O19/La0.7Ba0.3MnO3system. Composite components respectively Ba0.5Sr0.5Fe11.7Mn0.15Ti0.15O19and La0.7Ba0.3MnO3were prepared through mechanical alloying route employing a planetary ball mill for 20 hrs. The two milled powders were sintered at a temperature 1100 °C for 10 hours to ensure the crystallization towards fully crystalline materials. Composites with 2 different compositions were studied by FTIR and VNA from which results were compared with that of each component. Results of the investigation concluded that, the composite of Ba0.5Sr0.5Fe11.7Mn0.15Ti0.15O19/La0.7Ba0.3MnO3system is a good microwave absorbing material in the frequency range 9 GHz-15 GHz, particularly, sample with coded A03B07 has a wide range frequencies absorption.

Microwave Absorbing Properties of MnO2/Ni-Zn Ferrite/Graphite Structural Composite

2012 ◽  
Vol 535-537 ◽  
pp. 201-205 ◽  
Author(s):  
Jing Lan Deng ◽  
Ke Huang
Keyword(s):  
Zinc Ferrite ◽  
Layer Structure ◽  
Microwave Absorbing Properties ◽  
Matching Layer ◽  
Nickel Zinc ◽  
Zn Ferrite ◽  
Structural Composite ◽  
Absorbing Material ◽  
Microwave Absorbing ◽  
Absorbing Layer

In order to get high microwave absorbing properties, a new kind of three-layer structure composite absorption material was designed and prepared for optimal attenuation. Manganese Oxide was used as the absorbent in the matching layer. Nickel-Zinc ferrite (Ni-Zn ferrite) was used as the absorbent in the dielectric layer and Graphite was used as the absorbent in absorbing layer. The effects of different proportions of absorbents on the microwave absorbing properties were investigated. The results shows that the maximum wave absorbing peak of the 11# sample with the thickness of 5mm is −38.54dB at 14.35GHz and had a bandwidth of 7.1GHz (R<−10dB). This is very important in the design and application of absorbing material.

scholarly journals Electromagnetic response from multilayer composite coatings based on carbonyl iron, ferroelectrics and MWCNTs at microwave

2019 ◽  
Vol 30 ◽  
pp. 07011
Author(s):  
Grigoriy E. Kuleshov ◽  
Alexey V. Sbrodov ◽  
Tatyana N. Shematilo
Keyword(s):  
Experimental Study ◽  
Composite Materials ◽  
Carbonyl Iron ◽  
Composite Coatings ◽  
Dielectric Constants ◽  
Electromagnetic Response ◽  
Multilayer Composite ◽  
Frequency Range ◽  
Electromagnetic Characteristics ◽  
Frequency Dependences

The electromagnetic characteristics of composite materials based on carbonyl iron, ferroelectrics, and MWCNTs were studied in this article. The complex magnetic and dielectric constants of the experimental samples were measured in the frequency range from 1 GHz to 18 GHz. The results of calculation and the experimental study of the frequency dependences of the reflection coefficient on a multilayer composite coating located on a reflective surface are presented.

Research on New Technology to Control Highway Semi-Rigid Base Asphalt Pavement Cracks

2011 ◽  
Vol 194-196 ◽  
pp. 1632-1638
Author(s):  
Hong Liang Deng ◽  
Xiao Yin Fu ◽  
Wen Xue Gao ◽  
Ting Ting Ni ◽  
Kai Jiang Chen
Keyword(s):  
Composite Materials ◽  
Theoretical Calculations ◽  
Asphalt Pavement ◽  
New Technology ◽  
Service Level ◽  
Self Control ◽  
Good Effect ◽  
Rigid Base ◽  
The Road ◽  
Absorbing Layer

The methods of controlling Highway semi-rigid base asphalt pavement cracks and other diseases are always hot fields of road engineering and academic circles. The existing methods are on some degree efficient on delaying the formation and extension of cracks, but the effect is limited with different methods and various mechanisms of preventing cracks. Base on force analysis of pavement, this article presents a new technology of crack controlling which uses intelligent composite materials interlayer. By adding a stress absorbing layer between the asphalt surface layers or the semi-rigid base layers with low modulus, good toughness, self-adaptability and self-control ability, the intelligent composite materials interlayer has a good effect on controlling cracks which has been proved by the theoretical calculations and experimental analysis. As a result, the intelligent composite materials interlayer could efficiently prevent and delay the formation and extension of cracks, the safety and comfort of highway could be improved significantly while the cost of construction and maintenance decreasing. And the service level and social image of the road could also be improved effectively. This research has important academic and application value.

scholarly journals Study of the influence of Carbonyl iron particulate size as an electromagnetic radiation absorbing material in 12.4 to 18 GHz (Ku) Band

2018 ◽  
Vol 17 (4) ◽  
pp. 619-627 ◽  
Author(s):  
Ana Paula S. Oliveira ◽  
Aline C. Rodrigues ◽  
Sandro F. Quirino ◽  
Diego Edissón F. Vergara ◽  
Simone S. Pinto ◽  
...  
Keyword(s):  
Electromagnetic Radiation ◽  
Carbonyl Iron ◽  
Particulate Size ◽  
Absorbing Material ◽  
Ku Band

scholarly journals Flexible Broadband Metamaterial Perfect Absorber Based on Graphene-Conductive Inks

Photonics ◽  
2021 ◽  
Vol 8 (10) ◽  
pp. 440
Author(s):  
Le Van Long ◽  
Nguyen Sy Khiem ◽  
Bui Son Tung ◽  
Nguyen Thanh Tung ◽  
Trinh Thi Giang ◽  
...  
Keyword(s):  
Impedance Matching ◽  
Optical Filters ◽  
Wide Frequency Range ◽  
Absorption Feature ◽  
Perfect Absorber ◽  
Frequency Range ◽  
Absorption Mechanism ◽  
Polarization Insensitive ◽  
Metamaterial Perfect Absorber ◽  
High Absorption

In this work, we proposed a flexible broadband metamaterial perfect absorber (FBMPA) by exploiting a pasted conductive-graphene ink on a polyimide substrate. For the flat FBMPA, an absorption over 90% was found to cover a wide frequency range (from 7.88 to 18.01 GHz). The high-absorption feature was polarization-insensitive and regarded as stable with respect to the oblique incidence up to 30 degrees of electromagnetic wave. The high absorption was maintained well even when the absorber was wrapped. That is, the FBMPA was attached to cylindrical surfaces (with the varying radius from 4 to 50 cm). For both flat and curved states, the absorption mechanism was explained by the perfect impedance matching and the dielectric loss of the proposed absorber. Our work provides the groundwork for the commercialization of future meta-devices such as sensors, optical filters/switchers, photodetectors, and energy converters.

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